Carburetor



prim 79 W36.

J. IDOLZA CARBURETOR Filed April l5, 1929 To conduct fuel from the pipe 2S into the lower compartment of the pump housing, there is provided a pipe fl'l, which opens at one end into the interior of the boss 2l and at its opposite end into the upper portion of the lower compartment To prevent discharge of fuel from the lower compartment of the pump housing through the pipe lll, there is provided a check valve To conduct fuel from the lower compartment of the pump housing to the nozzle di from which fuel is adapted to be discharged into the mixture passage at a pointl adjacent that at which fuel is discharged thereinto from the high speec. nozzle fl, there is provided a pipe which corninunicates one end with the lower end of the cylindrical portion of the lower housing part and at its opposite end with the lower end of the nozzle To operate the pump upon movement of the throttle valve there is provided an arm which is integral with the throttle valve operating arm and a link 52' which is pivotally connected to the arm til and and to the piston rod at l'n order that the pumpI may function at all engiite speeds, the length of the arm 5l should be such that the distance through which the pivot 5d travels in a direction parallel to the axis of the cylinder as the throttle valve is moved from fully closed to fully opened position is suhstantially equal to or is less than the distance between the lower end of the piston. Si? and the lower end of the cylinder elfi when the throttle valve is in fully closed position.

Before the engine on whichthe carburetor is installed is started, sufficient liquid preferably oil, of the type of which the viscosity increases as its temperature is lowered and decreases as its temperature is raised, to lill the space between the diaphragm ll and the lower end of the piston 3l' when the throttle valve is in fully closed position is placed in the upper compartment G2 of the pump housing. During operation of the engine, the fuel pump 253 which is connected to the pipe 23 maintains a supply of fuel in the float bowl l l and keeys the lower compartment of the pump housing lled with fuel. It will be understood, of course, that the spring l5 is of sufficient strength to keep the valve dlclosed against the pressure of the fuel forced into the lower compartment t3 by the fuel pump 29. When the throttle valve is opened to start the engine, or when, with the engine operating at any given speed, the throttle valve is further opened to increase the speed of the engine, the piston 3l is moved downwardly in the cylinder 3i and, through the intermediary of the volume of liquid and the diaphragm lll, opens the valve 44 and forces fuel from the lower compartment of the pump housing through the nozzle 49 into the mixture passage l2 and thus supplies the increased amount of fuel which ls desired during acceleration periods. As the piston moves downwardly in the cylinder, a quantity of the liquid 55 which varies inversely with the viscosity of the liquid and, therefore, with the temperature of the liquid leaks between the side walls of the cylinder and the piston, into the portion of the cylinder 34 which is above the -piston, which causes the amount of fuel supplied to the mixture passage I2 through the nozzle 49 to vary inversely with the temperature of the engine. This leakage of the liquid 55 past the piston continues, even after downward movement of the piston has ceased, until the spring 46 causes the valve 44 to be seated and interrupts communicatlon between the upper and lower portions aoaaaos of the lower compartment KS3 of the pump housing. l

When, with the engine operating at any given speed, the throttle valve is moved toward closed position, the piston il is moved upwardly in the cylinder S.'- and. any of the liquid 55 which has collected above the piston drains through the openings 38 into the portion of the upper cornpartrnent [l2 which is below the piston.

DThe carburetor which is shown in Figure 2 of drawing differs from that which is shown in ligure l only in the means for supplying additional fuel to the mixture passage during acceleration periods. rf'o the parts of the carburetor 'which are the same as the corresponding parts of the carburetor shown in Figure l, the same reference characters have been applied, and, for this reason, a description of these parte will be unnecessary.

rlhe means for supplying additional fuel to the mixture passage i2 of the carburetor shown in Figure 2 during acceleration periods includes a pipe Gil connected at one end to the boss 2l, in the same manner as the pipe fil is connected to the boss 2l in Figure l, and opening at its opposite end into the interior of a valve casing Gl in which is located a suitable valve adapted to be operated by the arm G2 to control the passage of fuel through the interior of the valve casing. The lower end of a nozzle from which fuel is adapted to be discharged into the mixture passage l2 at a point adjacent that at which fuel is discharged thereinto from the high speed nozzle 22, communicates with the interior of the valve casing on the side of the valve opposite that on which the pipe il@ is connected thereto so that the valve controls the passage of fuel from the pipe Gil into the nozzle G3.

'lfo the free end of the arm G2 is pivoted a rod on the upper end of which is carried a cyl- 1in-:ler E55 of which the upper end is closed by a head GG through which extends a vent opening Gil. A piston G8, to which is rigidly secured a piston rod il@ which extends through the head to a point outside of the cylinder, and through which extends an opening 'lil controlled by a flap valve ll, is tted rather loosely in the cylinder.

To open the valve, which controls the passage of fuel from the pipe into the nozzle 83 and which is normally closed by a spring l2 which is secured to the arm 62 and the body of the carburetor, as the throttle valve is opened to increase the speed of the engine, there is provided an arm 'i3 which is integral with the throttle valve operating arm 26 and which is connected by a pivot pin 'M to the outer end of the piston rod 69. For reasons, which will be obvious, the effective length of the arm 'I3 should be such that the distance, through which the pivot 14 travels parallel to the axis of the cylinder as the throttle valve is moved from fully closed to fully opened position, is substantially equal to or is less than the distance between the lower end of the piston 68 and the lower end of the cylinder 65 when the throttle valve is in fully closed position.

Before the engine on which the carburetor is installed is started, sufficient liquid 55, of the type hereinbefore described, to illl the space within the cylinder 65 between the bottom thereof and the lower end of the piston 68 when the throttle valve is in fully closed position is placed in the cylinder 65. During operation of the engine, the fuel pump 29 maintains a supply of fuel in the float bowl Il and in the pipe 60.

aoeaaea "When, with the engine operating at any given speed, the throttle valve is further opened to increase the speed of the engine, the piston rod lit, and, through the intermediary of the piston til and the body of liquid t5, the cylinder til, and the rod til are moved downwardly. Downward movement of the -rod tl moves the valve operating arm lil against the resistance of the spring lf and establishes communication between the pipe t@ and the nozzle tt, with the result that the fuel pump'f@ forces fuel from the pipe tt into the nozzle l(it and therefrom into the mixture passage if, thus supplying the additional amount of fuel desired during acceleration periods.

As hereinbefore intimated, the force necessary to movethe valve operating arm tif to a position in which communication is established between the pipe t@ and the nozzle tt is transmitted to the arm tl. through the intermediary of the body of liquid till by the pressure of the piston t@ on the upper surface of the liquid. As a consequence of this application of pressure to the surface of the liquid, a portion of the liquid lit is forced between the piston lill and the walls of the cylinder tb into the portion of the cylinder above the piston. As hereinbefore explained, the volume 0f the liquid bb which thus leaks around the piston will vary inversely with the temperature of the engine and, consequently, the amount that the valve, which controls communication between the pipe lill and the nozzle t3, is opened and the amount of fuel supplied to the passage if through the nozzle lid will vary inversely with the temperalture of the engine. Leakage of liquid tt from the lower to the upper side ofl the piston til will continue, even after movement of the throttle valve has ceased, due to the tendency of the spring 'lf to move the valve operating arm tf to the position in which the valve is closed, until the arm abuts against the stop 'it and the valve is closed and communication between the pipe tu and the nozzle t3 is interrupted.

When, with the engine operating at any given speed, the throttle valve is moved toward closed position, the piston tt is moved upwardly in the cylinder tt and any of the liquid ill which has collected above the piston drains through the opening 'it into the portion of the cylinder below the piston.

Although l have shown and described preferred embodiments of my invention, it is to be understood that this has been done merely by way of example, and not by way of limitation, and that the scope of my invention is limited only by the appended claims.

ll claim:

l. In a caburetor, a fuel pump which includes a housing, a flexible diaphragm within the housing, a valve secured to the diaphragm, and means to flex the diaphragm.

2. In a carburetor, a fuel pump which includes a housing, a flexible diaphragm within the housing, a valve secured to the diaphragm, and means to Hex the diaphragm including, a body of liquid of which the viscosity decreases vas its temperature increases, and a piston adapted to exert pressure orf the body of liquid.

3. ln a carburetor, a mixing chamber, a throttle valve, a pump which includes a housing for injecting fuel into the mixing chamber, a ilexible diaphragm within the housing, and means including a body of liquid on which pressure is exerted when the throttle valve is opened to iiex the diaphragm and inject fuel into the mixing chamber when the throttle valve is opened.

ll. The invention claimed in claim plus a valve secured to the diaphragm.l

5. lin a carburetor, a throttle-operated pump for supplying fuel to the mixture passage of the carburetor and which includes a housing, a flexible diaphragm within the housing, a valve to control the discharge of fuel from the pump secured .to the diaphragm, and means to flex the lill diaphragm including, a-body of liquid, and a.

piston operatively associated with the throttle and adapted to exert pressure on the body of liquid.

6. In a fuel supply system, a carburetor having a mixing chamber and a fuel reservoir, common means for supplying fuel to the fuel reservoir for normal operation and accelerating fuel to the mixing chamber under pressure, .and manually operable means responsive to'temperature variations for controlling the discharge of accelerating fuel into the mixing chamber.

7. In a fuel supply system, a carburetor having a mixing chamber and a fuel reservoir, a fuel pump furnishing fuel to the carburetor under pressure, a connection from the pump to the fuel reservoir for supplying the normal fuel requirements of the carburetor, a connection from the pump to the mixing chamber for supplying auxiliary fuel thereto under pressure, and manually operable means differentially operative under ytemperature variations for controlling said named connection.

8. In an internal combustion engine, a mixing chamber, a throttle valve to regulate the flow of combustible mixture from the mixing chamber to the engine, mechanism for maintaining fuel under pressure during operation of the engine, a passage through which fuel may be advanced into the mixing chamber byvirtue of the pressure exerted on it by the mentioned mechanism, a fuel valve in the passage, and means through which the fuel valve is moved toward its opened position when the throttle valve is moved toward its opened position, the last mentioned means including a thermo-sensitive element so constructed and arranged that-the volume of fuel advanced into the mixing chamber through the mentioned passage when the throttle valve is moved toward its opened position a given extent varies inversely with the temperature.

9. In an internal combustion engine, a mixing chamber, a throttle valve to regulate the flow of combustible mixture from the mixing chamber to the engine, mechanism for maintaining fuel under pressure during operation of the engine, a passage through which fuel may be advanced into the mixing chamber by virtue of the pressure exerted on it by the mentioned mechanism, a fuel valve in the passage, and means through which. the fuel valve is moved toward its opened position when the throttle. valve is moved toward its opened position, the last mentioned means being so constructed and arranged that the fuel Valve may move to its closed position without movement of the throttle valve and including a thermo-sensitive element so constructed and arranged that the volume of fuel advanced into the mixing chamber through the mentioned passage when the throttle valve is moved toward its opened position a given extent varies inversely with the temperature.

JOHN DQLZA. 

